Roof flashings of various types have long been employed to seal around pipes extending through roofs and other exterior walls of houses and other buildings. Such pipes are used, for example, as conduits for electrical or other wiring, or as vent stacks for venting interior plumbing to the atmosphere.
It is also generally known to provide such roof flashings with different diameter seals in order to permit the same roof flashing to be used to establish a weather-tight seal with more than one size pipe. These roof flashings may include a plurality of frangible sections that permit one or more smaller diameter seals to be selectively removed so that one or more larger diameter seals may be used to establish the desired weather-tight seal with larger diameter pipes. Heretofore, a major drawback of these roof flashings was that the frangible sections were either too difficult to remove, or were too easily removed, thus subjecting the roof flashings to potential premature failure.